Ternary TiO2/MoSe2/γ-graphyne heterojunctions with enhanced photocatalytic hydrogen evolution

Photocatalytic water splitting for hydrogen evolution is widely considered as a clean, green, and renewable route for solar energy conversion and storage. In this work, we fabricated ternary TiO2/MoSe2/gamma-graphyne nanocomposite and demonstrated its superior photocatalytic hydrogen evolution activity. The samples were investigated by transmission electron microscopy, UV-Vis diffuse reflectance spectra, electrochemical impedance spectroscopy, and photoluminescence spectra. The optimized sample exhibited a high H-2 production rate of 16 mu mol h(-1), which was 3.2-fold as high as that of binary TiO2/MoSe2 and 6.2-fold as high as that of pristine TiO2. The enhanced photocatalytic activity is mainly because of the higher light-harvesting capacity, more active edge sites, and more charge-transfer channels induced by the multicomponent heterojunction through a cascade-driven electronic mechanism. This work presents a practical way to design noble-metal-free photocatalysts for solar energy-driven water splitting by band-engineering tailoring.